Geraniums (Geranium spp. and cvs, USDA Hardiness Zones 3–8) are terrific. It really is that simple. We could talk about their landscape versatility, cultural adaptability, and superior ornamental traits. Or we could talk about their sheer variety: There are about 300 species and a plethora of cultivars and hybrids in the world. But geraniums are simply awesome garden plants because of their beauty and their tried-and-true reputation. Despite these good traits, there are, unfortunately, a few less-than-stellar varie­ties out there, and nobody wants to be the one to spend their money on a stinker. That is why I decided to put more than 180 of them to the test, and you’ll find my conclusions on many of those trialed in the pages that follow.

My love of geraniums began when I first saw the luminous flowers of ‘Johnson’s Blue’, certainly one of the most well-known and beloved cultivars of all time. But when I trialed it, I found ‘Johnson’s Blue’ to be a lax plant with a penchant for floppiness and a fairly short bloom period. Although it was the go-to blue geranium for many years, it has been surpassed by an array of newer and more exciting selections.

Until we started our trial, my familiarity with geraniums—aside from the most popular garden staples—was somewhat lacking. But I know gardeners who, astonishingly, have never grown a single geranium. Perhaps that is because there are so many to choose from—maybe too many. I also wonder if gardeners just assume that geraniums are all the same or if the over­popularity of a few select varieties has created a comfort zone that keeps gardeners from straying off the path. After 15 years of testing, I’ve thankfully discovered a vast trove of indispensable geraniums—as well as a few that I wish I’d never laid eyes on.

Rozanne (‘Gerwat’) is unquestionably the most popular geranium today and certainly deserving of the accolades it has received, including the 2008 Perennial Plant of the Year and Royal Horticultural Society’s Award of Garden Merit. The white-eyed, purple-blue flowers are not always present in great quantities, but the plant is perpetually in bloom. I’m especially fond of the iridescent flowers in autumn, when cool weather sets in and not much else is blooming. Rozanne’s large, mounded habit with trailing flower stems is well suited to massing, but a single plant shines on its own, too. Because the flowers are sterile, they do not produce seed and, therefore, bloom for an extended time. In my garden, I grow Rozanne with the lavender-and-creamy-white blossoms of ‘Mrs. Robert Brydon’ clematis (Clematis ‘Mrs. Robert Brydon’, Zones 4–9); this sublime pairing is a hit for several weeks in late summer.

Everything about ‘Orion’ is supersize—from the abundance of the nearly 2-inch-wide, purple-blue flowers to its robustly spreading stems. At 30 inches tall and 6 feet wide, ‘Orion’ is a bit of a bruiser, topping the list as the largest geranium in the trial. Despite its size, ‘Orion’ never seems bulky, thanks to its fine-textured, dissected leaves. Like many geraniums, new leaves emerge as flowering winds down, ultimately pushing the floral stems away from the new growth. This is your cue to shear the old stems back to the base and to let the new leaves have their day.

It’s true that I have quite a few favorites when it comes to geraniums, but if pushed to choose just one for my garden, I would likely pick bigroot geranium (G. macrorrhizum). It’s one of the easiest plants I know of to grow: It is adaptable to sun or shade, is drought tolerant, and doesn’t need shearing. And it’s beautiful, too, with magenta-pink to white flowers in spring; lush foliage that turns red, orange, and burgundy in fall; and a refined spreading habit. Some of its many cultivars have unique flower colors—including ‘Lohfelden’, which has elegant, soft pink blooms, and ‘Czakor’, which boasts lusty, deep magenta blossoms. Bigroot geraniums are easily distinguished from other species by their slightly sticky, aromatic foliage; the scent is variably described as “minty,” “medicinal,” or “malodorous.”

Although it is no longer the most popular geranium in town, I still love ‘Brookside’. In our trial this variety had a compact, well-mannered habit that was far superior to the floppy ‘Johnson’s Blue’. In my own garden—where it gets more competition—‘Brookside’ is a bit rambunctious, but the pretty pale-eyed flowers are still delightful as the stems weave and wind through their neighbors. The flowers are reminiscent of ‘Johnson’s Blue’ but are darker with overlapping petals. Once ‘Brookside’ has finally exhausted itself in midsummer, I cut the stems back hard to encourage new leaves. An added bonus are the finely dissected leaves, which turn red and burgundy in autumn.

Standing out in a field of blue-flowered geraniums requires a little something extra. Golden chartreuse leaves flushed with red are just the thing that set Blue Sunrise (‘Blogold’) apart. The vibrant spring leaf color, which is enhanced in sunlight, fades to yellowish green just as the lavender-blue flowers open in late spring. Blue Sunrise is believed to be a hybrid of yellow-leaved ‘Ann Folkard’ and blue-flowered ‘Buxton’s Variety’ geranium (G. wallichianum ‘Buxton’s Variety’).

‘Sweet Heidy’ is touted for its unique tricolored flowers of lavender-blue, pink, and white. But that’s a somewhat deceptive description because the three colors aren’t present on the flower at the same time. The fresh flowers are pinkish purple with a pale eye, and as they age, the purple morphs into a bluish color.

Quibbling about the flower color does not lessen the remarkable floral display because the blooms are plentiful from late spring into fall. ‘Sweet Heidy’ looks like a pink-flowered Rozanne because of its mounded habit and trailing stems. The rambling stems enable this plant to look great in hanging baskets, in containers, or dangling over low walls.

At first glance, ‘Elizabeth Ann’ (G. maculatum ‘Elizabeth Ann’) is extremely similar to ‘Espresso’ geranium, but in the end, I prefer ‘Elizabeth Ann’ for its superior floral and foliar qualities. Its lavender-pink flowers with nicely overlapping petals are significantly darker than ‘Espresso’. Both cultivars have distinctive, chocolatey bronze–colored leaves in spring, which eventually fade to a summer mix of bronze and green. But the more lustrous leaves of ‘Elizabeth Ann’ bring an unexpected brightness to a shady garden. Both cultivars reseed plentifully and appear to come true from seed, but they express some seedling variability, too; we discovered a number of seedlings, for example, with superior leaf color to either cultivar.

 

 

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Everything You Need to Know About Geraniums

 

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